The present invention relates to controlled motion mechanical members used as a mechanical manipulator and, more particularly, to a motion controllable, anthropomorphic mechanical manipulator providing some of the capabilities of an upper human torso.
A need for increased automation in the workplace, especially in those workplace environments unsuitable for humans, and a desire to increase the use of animated figures depicting humans or other characters of ten in entertainment situations, has led to substantial efforts in the development of robotics. As a result, substantial advances have occurred in many aspects of robotics.
An important aspect in robotics is the controlling of mechanical manipulators, the portion of a robot used to change the position or orientation of selected objects. In may instances, such manipulators are desired to have motion capabilities similar to those of a human chest, shoulder, arm, wrist and hand, or portions thereof.
Providing a mechanical manipulator simulating such portions of the human torso presents a difficult design problem. The chest portions of a human supporting a shoulder can be considered to have two degrees-of-freedom in motion possibilities available to it, and the shoulder supporting the arm can be considered to have three degrees-of-freedom in motion possibilities available to it. In addition, the elbow can be considered to have a single degree-of-freedom in its possible motion and the wrist can be considered to have three degrees-of-freedom in motion possibilities available for it. Finally, the human palm can be considered to have a degree-of-freedom in its relative motion possibilities while the fingers and thumb thereon can be considered to have four degrees-of-freedom in the motion possibilities thereof.
A number of mechanical joints or mechanical manipulators have been proposed which attempt to exhibit the motion possibilities of the corresponding human joints, and some of these proposals have actually achieved corresponding capabilities to a significant degree. These joints typically have a base on which one side of the joint is fastened, and from which a force imparting arrangement is provided to operate movable members in this fastened portion of the joint. Mechanical transmission arrangements then couple this motion on this fastened side of the joint to the controlled side of the joint to cause that portion to correspondingly move.
However, such joints have of ten been constructed using a substantial number of parts causing significant expense, and with the result that they are of ten difficult to assemble. Further, such joints of ten fail to have the controlled portion thereof exhibit the desired dexterity and range of motion. In addition, the construction have of ten exhibited bulky geometries which do not appear much like those of the human counterparts. Also, control of the controlled side of the joint has of ten been insufficient in the operator not having convenient controlling arrangements available. FIG. 1 shows a joint, mechanical manipulator, or controlled member motion system, 10, which can have a very large output operating range in various configurations over which it is free of singularities, and which is operated by various force imparting devices directly or through various drive trains. A compact, ruggedized version of manipulator 10 is shown in FIG. 1 using yoke and shackle arrangements to rotatably secure the pivoting links provided therein.
Thus, FIG. 1 shows a perspective view of manipulator 10 in which manipulator 10 is positioned on a mounting arrangement, 11, which can be connected with an electric motor arrangement, unseen in these figures, that can rotate mounting arrangement 11 in either the clockwise or counterclockwise direction as selected by the user to thereby carry the remainder of joint or manipulator 10 correspondingly with it in these directions. Directly supported on mounting arrangement 11 is a base support, 12, shown as a rounded corner rectangular solid structure, though different geometrical shapes can be used, having four arms extending out from the main body of the support at the four thickness surfaces thereof initially parallel to the large surfaces of that support, and then bending at right angles away from mounting arrangement 11. These extending arms each thereby form something of a xe2x80x9cUxe2x80x9d shape to provide a capture space between the main support body of base support 12 and itself to result effectively in a yoke to rotatably accommodate the ends of pivoting links (described below) therein which are secured there by the use of a pin extending through the arm and pivot link end into the main body that allows the pivot link to rotate thereabout. A corresponding shroud plate extends from the main body of support 12 to each of these arms on the side of its capture space opposite the side thereof through which pivoting link secured therein extends to add support to that arm.
Support 12 has an opening, 13, (unseen in FIG. 1) extending along the central axis of rectangular symmetry for support 12 extending out from mounting arrangement 11 to parallel the outer sides of support 12. Opening 13 extends through support 12 and from there through mounting arrangement 11 along the axis about which it is capable of rotating manipulator 10 so as to be capable of permitting some desired means extend therethrough such as electrical wiring, optical fibers or some mechanical arrangement, or some combination thereof.
Also shown supported directly on mounting arrangement 11 are a pair of linear actuator support pedestals, 14, (unseen in FIG. 1) connected to mounting arrangement 11 each of which is shown supporting a linear actuator along with the direct mechanical interconnection between that linear actuator and the remaining portions of manipulator 10. That is, a pair of linear actuators, 15 and 16, are each rotatably mounted in the corresponding one of pedestals 14 by an outer body thereof, 17. Linear actuator 16 has an actuator output shaft, 18, extending from outer body 17 thereof which is directly affixed to a clevis, 19. Clevis 19 on output shaft 18 of linear actuator 16 is directly and rotatably affixed to a pivoting link, 20, by a further pin, 21, through an opening in a boss, 22, extending from pivoting link 20 (which pin may be in bearings or a bushing mounted in boss 22 positioned about the opening therein). Linear motion by output shaft 18 in actuator 16 outward or inward causes clevis 19 to correspondingly move away from or toward body 17 of linear actuator 16.
Such motions by clevis 19 forces pivoting link 20 to in turn rotate one way or the other about a pin, 23, around a rotation axis extending through pin 23 that is more or less perpendicular to the length of link 20. Pin 23 is directly affixed in an opening in the central rectangular portion of base support 12 and in an opening in an extending arm of base support 12 as two sides of a yoke to extend through the capture space therebetween and through an opening in the end of pivoting link 20 (which pin may be in bearings or a bushing mounted in the opening in link 20, and pin 23 could be a pivot screw (shoulder bolt) rather than a pin. Such a pivot screw is threaded at the end thereof opposite the screw head only a relatively short distance in from that end to permit its being screwed firmly into base support 12 but only a fixed distance therein to assure a selected length of the screw is exposed outside support 12 The surface of this exposed portion of the screw from support 12 to the screw head is smooth especially if no bearing or bushing is used between this screw and pivoting link 20 lubrication at the least would be likely to be used in this situation).
An identical linear actuator translation drive system for forcing rotational motion of another pivoting link is provided in connection with linear actuator 15. As seen in FIG. 1, a clevis, 19xe2x80x2, is affixed to output shaft 18 of linear actuator 15 with the other end of clevis 19xe2x80x2 being affixed by a pin, 21xe2x80x2, to a further pivoting link, 20xe2x80x2, rotatably connected to base support 12, through an opening in a boss, 22xe2x80x2, extending from pivoting link 20xe2x80x2. Thus, again, linear motion by output shaft 18 in actuator 15 outward or inward causes clevis 19xe2x80x2 to correspondingly move away from or toward body 17 of linear actuator 15 which forces pivoting link 20xe2x80x2 to correspondingly rotate in either a clockwise or counterclockwise direction. Pivoting link 20xe2x80x2 can rotate on bearings about a pin or screw, 23xe2x80x2, not seen in these figures, positioned in an opening therein at its end with pin or screw 23xe2x80x2 affixed to the sides of the corresponding yoke in base support 12, and pivoting link 20xe2x80x2 again rotates around an axis extending therethrough more or less perpendicular to the length of link 20xe2x80x2.
Pivoting links 20 and 20xe2x80x2 are two pivoting links in a plurality of lower pivoting links in manipulator 10, this lower plurality further including two other pivoting links, 20xe2x80x3 and 20xe2x80x2xe2x80x3 (not all seen in FIG. 1), with extending bosses, 22xe2x80x3 and 22xe2x80x2xe2x80x3 (not all seen in FIG. 1). Bosses 22xe2x80x3 and 22xe2x80x2xe2x80x3 are unused in the present situation in which just two linear actuators are used to operate manipulator 10, but can be used with the use of further linear actuators. These last two pivoting links are each capable of rotating on bearings about a corresponding one of pins or pivot screws, 23xe2x80x3 and 23xe2x80x2xe2x80x3 (not all seen in FIG. 1), respectively, with the corresponding axis of rotation extending therethrough substantially perpendicular to the length of links 20xe2x80x3 and 20xe2x80x2xe2x80x3. Pins or pivot screws 23xe2x80x3 and 23xe2x80x2xe2x80x3 are again directly affixed in a corresponding opening in the central rectangular portion of base support 12 and in a corresponding opening in a corresponding extending arm of base support 12 in the capture space therebetween (which pin may be in bearings or a bushing mounted in each of these base support 12 openings so as to be positioned about that opening, and pin 23 could be a pivot screw rather than a pin). Each of pins or pivot screws 23, 23xe2x80x2, 23xe2x80x3 and 23xe2x80x2xe2x80x3 is affixed to base support 12 such that the corresponding one of the plurality of lower pivoting links rotatably coupled to base support 12 thereby rotates about an axis therethrough that intersects, and is perpendicular to the axis of rectangular symmetry of support 12 extending out from mounting arrangement 11, with these rotation axes being separated from adjacent ones by equal angles measured about the symmetry axis, here 90xc2x0.
The lower plurality of pivoting links 20, 20xe2x80x2, 20xe2x80x3 and 20xe2x80x2xe2x80x3, in addition to each having an end thereof being rotatably connected to base support 12 by the yokes effectively provided by the central rectangular portion and the corresponding extending arm of that base support as described above, also each have the opposite end thereof formed as devises with two spaced apart arms that are rotatably connected by four further pins or pivot screws, 24, 24xe2x80x2, 24xe2x80x3 and 24xe2x80x2xe2x80x3, to corresponding pivot holder shackle members, 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3. Each of these pivoting link devises has a shroud plate extending between the arms thereof on the side opposite that through which a corresponding shackle extends to add support to these two arms. Each of these pivot holder shackle members is formed as a bent link with an opening therethrough at each end to accept a pin extending through it (which pin may be in bearings or a bushing mounted in the link opening positioned about that opening therein), the bend in the link occurring along the width thereof between the two openings each provided near a corresponding end thereof. Each of these pivot holder shackle members 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3 has an end thereof captured in a shrouded clevis at the end of a corresponding one of the lower plurality of pivoting links 20, 20xe2x80x2, 20xe2x80x3 and 20xe2x80x2xe2x80x3 by a corresponding one of pins 24, 24xe2x80x2, 24xe2x80x3 and 24xe2x80x2xe2x80x3 extending through the opening in that bent link end into the arms of the pivoting link clevis on either side thereof.
The axis of rotation of each of the lower plurality of pivoting links 20, 20xe2x80x2, 20xe2x80x3 and 20xe2x80x2xe2x80x3 through a corresponding one of pins or pivot screws 24, 24xe2x80x2, 24xe2x80x3 and 24xe2x80x2xe2x80x3 in being rotatably coupled to a corresponding one of pivot holder shackle members 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3, and the axis of rotation of each of these links through a corresponding one of pins or pivot screws 23, 23xe2x80x2, 23xe2x80x3 and 23xe2x80x2xe2x80x3 in being rotatably coupled to base support 12 are, in each link instance, perpendicular to planes therethrough that for each link intersect one another at substantially right angles. These rotation axes for each of these pivoting links are also oriented in directions differing from those in an adjacent pivoting link, i.e. the next pivoting link thereafter around base support 12. This allows pivot holder shackle members 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3 to be moved by the corresponding pivoting links substantially with respect to base support 12, but for the same length links these pivot holder shackle members will always be in a plane common thereto, and will move about a circle in such planes. Although pivot holder shackle members 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3 are shown in these figures as extended bent links, this shape is not required but instead other geometrical shapes could be used.
Manipulator 10 is shown in these figures having a further upper plurality of pivoting links. Each of this plurality has an end thereof formed as a clevis formed by two spaced apart arms that is rotatably coupled to each of pivot holder shackle members 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3 by a corresponding one of a further set of pins or pivot screws, 27, 27xe2x80x2, 27xe2x80x3 and 27xe2x80x2xe2x80x3 (not all seen in FIG. 1) extending through the other end opening of such pivot holder shackle member not connected to a lower pivoting link to be affixed to the two arms of the clevis (which pin may be in bearings or a bushing mounted in the link opening positioned about that opening therein). Again, each of these pivoting link devises has a shroud plate extending between the arms thereof on the side opposite that through which a corresponding shackle extends to add support to these two arms by forming a shrouded clevis.
The axis of rotation of the corresponding one of this upper plurality of pivoting links, in being able to rotate about its pin or pivot screws 27, 27xe2x80x2, 27xe2x80x3 and 27xe2x80x2xe2x80x3, is directed so as to be more or less parallel to the length of the link. There is a corresponding one of a set of angles, 28, 28xe2x80x2, 28xe2x80x3 and 28xe2x80x2xe2x80x3, (not all seen in FIG. 1) of a selected angular magnitude between the axis of rotation of the pivoting link from the lower plurality thereof rotatably connected to each pivot holder member and the axis of rotation of the one of the upper plurality of pivoting links also rotatably connected thereto as shown in these figures set by the bend in the bent links forming the pivot holder shackle members. The selection of the magnitude of each of angles 28, 28xe2x80x2, 28xe2x80x3 and 28xe2x80x2xe2x80x3 effects the capabilities of manipulator 10 as will be described below.
Another set of pins or pivot screws, 29, 29xe2x80x2, 29xe2x80x3 and 29xe2x80x2xe2x80x3, (not all seen in FIG. 1) are each used at the opposite end of a corresponding one of such an upper plurality of pivoting links, 30, 30xe2x80x2, 30xe2x80x3 and 30xe2x80x2xe2x80x3 (not all seen in FIG. 1). If manipulator 10 is constructed symmetrically above and below a plane including each of pivot holder shackle members 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3, i.e., angles 28, 28xe2x80x2, 28xe2x80x3 and 28xe2x80x2xe2x80x3 in these figures being bisected by such a common plane, the upper plurality of pivoting links 30, 30xe2x80x2, 30xe2x80x3 and 30xe2x80x2xe2x80x3 can be identical in construction with each other and with each of the lower plurality of pivoting links 20, 20xe2x80x2, 20xe2x80x3 and 20xe2x80x2xe2x80x3. Although this is a significant economic factor in manufacturing significant numbers of joint or manipulator 10, this symmetry is not required for successful operation of such manipulators. However, the nature of the positioning of the output structure in such manipulators for a given rotation of the rotor shafts of motors 15 or 16 will change with differences in the portions of angles 28, 28xe2x80x2, 28xe2x80x3 and 28xe2x80x2xe2x80x3 above and below the horizon. Also, the lengths of pivoting links in the upper and lower pluralities thereof need not all be the same to have successful operation of manipulator 10 but, again, the pattern of the positioning of this output structure will change depending on such differences.
The output structure which is controlled in manipulator 10 by motion of linear actuators 15 and 16 has a hole, 31, provided therethrough to form a rounded corner rectangular solid, open center structure, though different geometrical shapes can be used, resulting in a manipulable support, 32. Manipulable support 32 has four arms extending out from the main body of the support at the four thickness surfaces thereof initially parallel to the large surfaces of that support, which then bend away at right angles generally toward mounting arrangement 11. These extending arms each thereby form something of a xe2x80x9cUxe2x80x9d shape to provide a capture space between the main support body of manipulable support 32 and itself to result effectively in a yoke to rotatably accommodate the ends of the upper pivoting links therein which are secured there by the use of the corresponding one of pins 29, 29xe2x80x2, 29xe2x80x3 and 29xe2x80x2xe2x80x3 extending through the arm and pivot link end into the main body that allows the pivot link to rotate thereabout. A corresponding shroud plate extends from the main body of support 32 to each of these arms on the side of the arm capture space opposite the side thereof through which the corresponding pivoting link secured therein extends to add support to that arm.
Again, various items can be extended through opening 31 such as electrical wiring or optical fibers or, in this output situation, a further mechanical device supported on support 32, or some combination of such features or other alternatives. Also, the output structure as represented by manipulable support 32 can be controlled in manipulator 10 by motion of a complementary set of linear actuators, 35 and 37, (not seen in FIG. 1 but referenced here to clarify certain subsequent figures) having their bases mounted in actuator support pedestals 14 and their output shafts connected to the two remaining lower pivoting links 20xe2x80x3 and 20xe2x80x2xe2x80x3 either instead of using actuators 16 and 15 connected to lower pivoting links 20 and 20xe2x80x2 as described above, or alternatively also using actuators 15 and 16 to provide greater force and stability.
Each of pivoting links 30, 30xe2x80x2, 30xe2x80x3 and 30xe2x80x2xe2x80x3 in the upper plurality thereof is rotatably coupled by a corresponding one of pins or pivot screws 29, 29xe2x80x2, 29xe2x80x3 and 29xe2x80x2xe2x80x3 to manipulable support 32. Here too, each of the plurality of upper pivoting links can rotate on bearings about a corresponding one of pins or pivot screws 29, 29xe2x80x2, 29xe2x80x3 and 29xe2x80x2xe2x80x3 positioned in an opening therein at its end with the corresponding one of pins 29, 29xe2x80x2, 29xe2x80x3 and 29xe2x80x2xe2x80x3 affixed to the sides of the corresponding yoke in manipulable support 32, and each of pivoting links 30, 30xe2x80x2, 30xe2x80x3 and 30xe2x80x2xe2x80x3 again rotates around an axis extending therethrough more or less perpendicular to the length thereof. These rotation axes are separated from adjacent ones by equal angles measured about the symmetry axis, here again 90xc2x0 because of the presence of four pivot links. Although the rotation axes of the pivoting links at the rotary couplings thereof to supports 12 and 32 are described as making equal angles with adjacent ones thereof as they occur about those supports, these angles need not be identical about either support, nor identical about one support with those about the other, to be able to position support 32 over a substantial angular range, though providing substantially such identities is of ten convenient.
Pivoting links 30, 30xe2x80x2, 30xe2x80x3 and 30xe2x80x2xe2x80x3 in the upper plurality thereof may be connected to the side of manipulable support 32 that is opposite to the side of base support 12 to which the corresponding one of pivoting links 20, 20xe2x80x2, 20xe2x80x3 and 20xe2x80x2xe2x80x3 in the lower plurality thereof is connected as shown in FIG. 1 or, alternatively, connected to manipulable support 32 on the same side thereof as the side of base support 12 to which the corresponding one of pivoting links 20, 20xe2x80x2, 20xe2x80x3 and 20xe2x80x2xe2x80x3 in the lower plurality thereof is connected. The axis of rotation of such a one of pivoting links 30, 30xe2x80x2, 30xe2x80x3 and 30xe2x80x2xe2x80x3 in the upper plurality thereof about its pin or pivot screw coupling it to support 32 extends through that pin or screw more or less perpendicular to the direction of the length of that link, and substantially parallel to the axis of rotation about the pin or pivot screw rotatably coupling the corresponding one of pivoting links 20, 20xe2x80x2, 20xe2x80x3 and 20xe2x80x2xe2x80x3 in the lower plurality thereof to base support 12. The correspondence here between upper and lower plurality pivoting links is established by each being coupled to the same one of pivot holder members 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3. Again here, as for the pivoting links in the lower plurality thereof, the axis of rotation of one of pivoting links 30, 30xe2x80x2, 30xe2x80x3 or 30xe2x80x2xe2x80x3 in the upper plurality thereof about its corresponding one of pins or pivot screws 27, 27xe2x80x2, 27xe2x80x3 or 27xe2x80x2xe2x80x3 is substantially perpendicular to a plane which intersects at substantially right angles that further plane which is substantially perpendicular to the axis of rotation of that link about its corresponding one of pins 29, 29xe2x80x2, 29xe2x80x3 or 29xe2x80x2xe2x80x3.
The various structural components of joint or manipulator 10 described in connection with FIG. 1 above are typically formed of a metal or metals, or alloys thereof, appropriate for the intended use, i.e. perhaps stainless steel for a medical use, aluminum or titanium where weight is a primary concern, etc. Many or all of these components could be molded polymeric materials instead.
The center of manipulable support 32 can essentially reach every point on a hemispherical surface about manipulator 10 (and in many link constructions, somewhat beyond such a surface) without the occurrence of loss of control singularity points anywhere in this range of motion. During such motion, as indicated above, pivot holder shackle members 25, 25xe2x80x2, 25xe2x80x3 and 25xe2x80x2xe2x80x3 will always intersect a common plane though a different plane at each location of manipulable support 32. Thus, there is a desire to use manipulator 10 with these capabilities, and to use other robotic structure improvements, to simulate portions of the human body.
The present invention provides a controlled relative motion system having first and second support structures, the first support structure having a first support offset structure extending along a first axis and the second support structure having a second support offset structure extending along a second axis, connected with an intermediate joint having a base member and a controlled position member that has an output carrier which can be angularly positioned with respect to the base member anywhere over a selected spatial surface. This intermediate joint base is affixed to an interior end of a selected one of the first and second support offset structures with the output carrier affixed to an interior end of that one remaining. A similar first support joint has a base member supported by and affixed with respect to the first support offset structure at an exterior end thereof opposite its interior end along the first axis. A second support joint, also similar to the intermediate joint, has a base member supported by and affixed with respect to the second support offset structure at an exterior end thereof opposite the interior end thereof along the second axis.
One of the first and second support joints as a base is coupled to a further controlled relative motion system having an extended open interior member rotatably coupled to the base for rotating about a corresponding interior member rotation axis along which a pair of spaced apart interior member sides extend so as to have an extended space therebetween. The extended open interior member is rotatably coupled to the base at an end thereof joining the interior member sides at one end of the extended space by a first shaft coupled thereto, and is further rotatably coupled to the base at an opposite end thereof also joining the interior member sides at an opposite end of the extended space by a second shaft coupled thereto.
Also, an output carrier has a pair of output carrier sides spaced apart by a recess space with these output carrier sides being joined in a joining structure on one side of the recess space. The output carrier is positioned to have the extended open interior member in its recess space so that the output carrier sides extend at least in part substantially parallel to the interior member sides to which they are rotatably coupled to rotate about a corresponding output carrier rotation axis substantially perpendicular to the interior member rotation axis. The output carrier is rotatably coupled to the extended open interior member by a follower shaft affixed to the output carrier and rotatably coupled to the extended open interior member.
An interior member first bevel gear is located in the extended space and affixed to the first shaft, and an output carrier first bevel gear is located in the extended space and affixed to the follower shaft to be engaged with the interior member first bevel gear. A plurality of force imparting means is mounted in the base with each of the first and second shafts being rotatably coupled to a corresponding one of these force imparting means.
This further controlled motion system with the output carrier as a base supports an articulated manipulating system capable of engaging selected objects having a subbase rotatably mounted on the base to have a single subbase rotation axis therethrough. A first linear actuator is coupled at one end thereof to the base and coupled at an opposite end thereof to the subbase to be capable of rotating the subbase about the subbase rotation axis. A first effector base is rotatably connected to the subbase to have a first effector rotation axis, and a second linear actuator is coupled at one end thereof to the subbase and coupled at an opposite end thereof to the first effector base to be capable of rotating the first effector base about the first effector rotation axis.
This further controlled motion system with the output carrier as a base also supports a shackle having a pair of arms spaced apart by a recess space which arms are joined in a joining bar on one side of the recess space, an effector base rotatably mounted at a pivot location thereof to and between the separated arms of the shackle so as to leave a recess space between an end of that effector base rotatably mounted to the shackle and the joining bar thereof, a pedestal affixed to the base relatively near to where the subbase is rotatably mounted on the base and having the joining bar of the shackle rotatably coupled thereto. A gripping extension is rotatably coupled to the effector base at an extension coupling location thereof spaced apart from the pivot location thereof, and an extension linear actuator is positioned adjacent to the effector base and coupled at one end thereof so as to have that end positioned at least in part in the recess space of the shackle with that remaining end of the linear actuator rotatably coupled to that gripping extension. Further, a pair of effector linear actuators is provided with each having an end thereof connected to the base at corresponding base connection locations thereon, and each having that opposite end thereof rotatably connected to an effector base at corresponding effector connection locations thereon. Thus, any substantial differentials in movement of these actuators cause corresponding substantial motions of the effector base towards a corresponding one of the base connection locations and so that substantial common movements of these actuators causes substantial motions of the effector base toward or away from both of the base connection locations.